Surface and Depth

In the 1950s, the psychologist J.J. Gibson outlined a number of cues to depth perception. A few rely on our binocular vision and therefore do not apply to 2-dimensional drawings and paintings. Others, however, are psychological rather than physiological in nature. As such, these depth cues are pictorial in nature and are applicable to drawing and painting on a 2-dimensional surface. In the following, I try to use simple terms and snippets of my own drawings and photographs to illustrate each of the depth cues that I consider to be relevant to drawing on location.

Convergence

Convergence of parallels: This is a key characteristic of linear perspective in which parallel lines appear to converge as they recede into the distance. Despite the usefulness of the other depth cues, linear perspective remains the structural scaffolding upon which to build a sense of spatial depth on the page.

Overlap

Overlap: Near objects overlap or partially block the view of objects farther away. Locating effective overlaps can be useful in selecting a viewpoint and composing a drawing.

Position

Position relative to the horizon: Objects below our eye level rise toward the horizon as they recede; objects above our eye level descend toward the horizon as they recede.

SizePerspective

Relative size: Objects known or assumed to be of similar size appear to shrink in size with distance from the observer.

TexturePerspective

Texture gradient: Surface texture appears to get finer and smoother with distance from the observer.

Shading

Shading and shadows: Contrasts in light and dark can convey the shape, form and depth of objects.

Atmosphere

Aerial perspective: Particles in the atmosphere affects the color and visual acuity of objects at varying distances from the observer; distant objects appear grayer or bluer and less distinct than nearer objects.

As we can see, scenes more often than not comprise a number of these depth cues operating simultaneously. Seeing how these depth cues occur in our real-life perception can aid our understanding of why things appear as they do, counter to what we know of the things we draw, which are often in conflict.

Casa das Canoas

EPSON MFP image

While in Rio de Janeiro a month ago, we had the opportunity to visit Casa das Canoas, the first residence designed by Oscar Niemeyer in 1952. It is a true gem, nestled in a beautiful hillside setting and displaying the characteristic flowing lines of Niemeyer’s architecture. Thanks to Caique Niemeyer, Oscar’s grandson, for allowing us the privilege of touring this fine example of modern architecture.

After doing a few sketches of the exterior and interior of the deceptively simple structure, I attempted to draw a plan to try to understand the two-dimensional origin of what I saw in three dimensions.

EPSON MFP image

To verify my plan, I perused several books on the architecture of Oscar Niemeyer but none contained a plan of this house. Upon returning to Seattle, I did an internet search and found this plan drawn by Jeff Hottinger, which is included next to the plan I drew.

In this age of digital 3D modeling where much design thinking and decision-making is made from a perspective viewpoint, it is still a useful mental exercise to try to imagine the orthographic relationships that plans and sections reveal and which perspective views do not. As designers, we should be able to think two-dimensionally as well as three-dimensionally.

Negative Spaces

Along with a few fellow architect-volunteers from the community service committee of the AIA Young Architects Forum, I met this morning with a group of middle schoolers attending the Northwest School Summer Camp. Our task was to introduce some basic drawing concepts to the young students. My topic was negative space, a concept that is somewhat difficult to grasp, especially when translating the in-between spaces that we see in real life into the two-dimensional shapes we draw on paper. After the session, I remembered an animation that I had created a while back when I was conceiving of a ebook on drawing. Here is an unedited version of Seeing Shapes.

SeeingShapes

Keep in mind that it is often easier to see shapes in a photograph and more difficult to see them when drawing on location from direct observation.

Black and White

With the rise of digital photography color has become pervasive, unlike the film era where black-and-white photography was prized for its confident and raw visual style. In the field of sketching, too, color sketches are often seen as richer and communicating more information than monochrome drawings, which many consider to be primitive and lacking emotion. Yet, utilizing a range of strokes, black-and-white sketches can express a wider range of feelings than one might expect…

from light and airy…

B&W1

to dark and heavy…

B&W2

from descriptive…

B&W3

to illusory…

B&W4

Act without Striving

Sometimes, we do our best work when we are the least concerned with the outcome.

Fresh1 Fresh2 Fresh3

By showing you these images, I do not mean to imply they are examples of my best work but there is a fresh quality to my drawings either when I don’t have the time to overthink a drawing or when I am demonstrating an idea or approach as I am teaching.

 

Contrast

Whenever I view one of my own drawings or see someone else’s work, my immediate, instinctive reaction is to ask: How could the drawing have been improved? Sometimes, the answer is better composition; at other times, it’s more context. But the more common response for me is increased contrast.

I’ve written about this before but it bears repeating that contrast is a critical part of both seeing and drawing. Without seeing contrast, we are not able to differentiate one thing from another. And without drawing contrast, we diminish the hierarchy that creates interest and focus in a sketch.

ConfuciusTemple

There are several kinds of contrast that we can use in a drawing. Perhaps the most obvious is distinguishing between heavy and light line work to enhance spatial depth—what is near versus what is further away.

Ookayama2

Another is contrasting areas of greater detail with spaces of lesser detail, or areas of precision with those of ambiguity.

WC2WC2bw

And in the case of watercolor sketches, it is definitely necessary to differentiate not hues but rather zones of tonal values.

Another View of Foreshortening

Print

Using the same broad outline of the Campo in Siena from two posts ago, I’ve overlaid the sketch with a diagram of the important points that I visualized in the scene—the extent of my view, the relative position of the Torre del Mangia, and the foreshortening of the Palazzo Pubblico.

CampPlanDiagram

To further illustrate the phenomenon of foreshortening, I’m using a plan diagram of the Campo to show where I stood as I sketched and my angle of view. You can compare the actual width of the Palazzo Pubblico, shown with the white arrow, with my foreshortened view of it, shown with the black arrow, and notice its position relative to the horizontal sweep of the Campo space.

You can also see, both in plan and in the perspective sketch, the positioning of the Torre about one-third of the way across from the right-hand edge of the view. I visualized diagonals to estimate the height of the Torre relative to the width of the space.

While these are necessarily optical judgments, not precise measurements, seeing these types of relationships and imagining them on the page as you set up a drawing on location are important steps in the process.

Foreshortening

Foreshortening

Foreshortening is the apparent change in form an object undergoes as it rotates away from our point of view. This phenomenon is usually seen as a contraction in size or length in the direction of depth, the amount of contraction depending on the degree of rotation. The more a line or plane is rotated away from our point of view, the greater its apparent contraction. You can easily see this as a door opens away from you. Gauging and drawing the phenomenon of foreshortening can be a bugaboo for sketchers because our mind can persuade us to draw what we know—the actual size or length of something—rather than how that thing might appear to the eye—its apparent size or length.

VirginiaV

To illustrate a case of foreshortening I want to use this view of the Virginia V that I sketched this past Sunday before the Seattle UrbanSketchers group met at the Museum of History and Industry for its January meeting. One of the reasons for gathering at MOHAI is the beautiful exhibit there of Gabi Campanario’s impressive work documenting the life and times of Seattle over the past six years for the Seattle Times.

The Virginia V, built in 1921 by Anderson & Company and launched in 1922, was part of the mosquito fleet that plied the Puget Sound waters largely between the First and Second World Wars. After WWII, the Virginia V changed hands several times as it served as an excursion vessel. It was placed on the National Registry of Historic Sites in 1973. Completely refurbished by the Steamer Virginia V Foundation, the Virginia V is now anchored at the south end of Lake Union and continues to be used for public excursions and private charters.

Print

In this view of the same Virginia V sketch, I’ve overlaid some markers to show the relationships that I gauged and used to control the foreshortening of the ship. The most important step is ensuring that the apparent length—from the prow on the left to where the hull curves away from our view on the right—is correctly foreshortened relative to the height of the prow. Then, I positioned elements, such as the wheelhouse and bridge, relative to the left and right extents. Note how I try to suggest the way the hull is curved from fore to aft. You can use the span of your hand, the shaft of your pen or pencil, or any similar means to gauge these measurements but it is an essential step in the process. Otherwise, your mind will strongly suggest that you should draw what you know rather than how it appears to the eye.

The First Lines…

When an architect, designer, or builder says that a building has “good bones,” this generally means that it is well built. Like others, however, I would extend the meaning of the phrase to include not just the sturdiness of a construction but also the soundness of its underlying organization and layout. A design with good bones should be able to endure flaws in workmanship or execution and gracefully accept the changes made to improve it.

Bones1

So it is also with a sketch. To begin a drawing done on location, we must first select an advantageous viewpoint that conveys a sense of place and frame the composition to fit on the page. Then, a crucial step is establishing the “bones” of the drawing—its basic structure—with the first lines we draw. I like to say that the number of lines is five but this, of course, is arbitrary. For some views only a few lines may be necessary while for others, more might be required to establish the structure of a drawing.

Bones2

Bones3

It is essential to understand that once this structure is established, changes can still be made to calibrate scale, improve proportional relationships, and adjust the positioning of elements. Drawing these first few lines is simply a way to block out the essential relationships on a page quickly, before expending too much time on a drawing only to find out that a portion might be misplaced or is out of proportion to the rest of the composition.

CampoSiena

Here is an example—a very quick outline of a view of the Campo in Siena that I did as a demonstration. With more time and better weather, I might have finished it but I think it is possible to see and visualize the space even in this incomplete state.

Drawing a Self-Portrait

Drawing a self-portrait was the initial assignment we used to give students at the outset of our design drawing class. The process we outlined was as follows:

“Have available a fine-tipped black pen capable of marking a sheet of clear acetate. Select a comfortable, seated position in front of a mirror and tape the acetate sheet to the mirror where your face appears. Carefully consider the shape, proportion, and features of your face.

With the pen and using a line technique, draw your portrait directly on the sheet of acetate. To do this, you must look through only one eye—your dominant eye. To find out which is your dominant eye, mark the tip of your nose on the mirror with both eyes open and then shutting each eye in turn. Seen through your dominant eye, the mark will hardly move; through the weaker one, the mark will shift considerably.”

SelfPortrait

This is my attempt, which I’ve flipped so that the image is as you would see me. It seems that I’m looking to my right but I was actually looking straight ahead. While the task itself does not take very long, it is difficult to keep your head steady while trying to trace the contours of your face. You also learn after a few tries not to draw every line you see! This was a fun exercise that not only introduced the students to drawing from observation but also helped us identify students before the age of digital cameras.